Infra-red (IR) proximity sensing systems, e.g. IR proximity detection requires proximity sensors that detect more than just a distance to an object (r coordinate in a polar coordinate system) to be able to reconstruct a 3-dimensional (3D) trajectory in space, e.g. for mobile applications e.g. (mobile) phones, tablet personal computers (pcs), laptops. Other applications are e.g. light source position detection or tracking e.g. solar trackers.
In another conventional arrangement, ultrasound sources and multiple microphones are used in addition to a photodiode to detect the trajectory of a light source. These solutions may have a large bill of materials and integration complexity.
In another conventional arrangement, cameras with 3D software reconstruction or time of flight systems are used to detect the trajectory. These solutions may be complex, power hungry and difficult to miniaturize.